Hallmarking Act 1973

3(1)A description of an article, or of the metal in an article, as “sterling” or (except in the phrase “Britannia metal”) “Britannia” is to be presumed to be an indication that the article, or the metal, is of silver.U.K.

(2)If “sterling” is the word used, the description is to be presumed to be an indication that the silver is of a standard of fineness of 925.

(3)If the word used is “Britannia” the description is to be presumed to be an indication that the silver is of a standard of fineness of 958·4.